Semiconductor solar cells can transduce light energy into electric energy. Generally speaking, the silicon solar cell consists of a P-N junction. When the photons in sunlight strike the surface of the semiconductor, electron-hole pairs will be induced by high-energy photons. The electron-hole pairs will move to the junction of the semiconductor and produce photocurrent within the loaded semiconductor.
Conventionally, solar cells are fabricated by doping the P-type silicon wafer with concentrated phosphorous to form an N.sup.+ diffusion region in the surface of the P-type silicon wafer. Then, electrodes are formed by means of screen-printing. The conventional method for fabricating solar cells will be illustrated in FIGS. 1A.about.1D.